Objective To discuss and evalue the effects and the advantages of pectoral is major myocutaneous flap in repair of defect caused by resection of tonsillar cancer. Methods The data were retrospectively summarized from 10 patients with recurrent tonsillar cancer after radical radiotherapy from January 1998 to December 2005, including 7 cases of squamouscell carcinoma, 2 cases of undifferentiated carcinoma, and 1 case of adenoid cystic carcinoma. There were 8 males and 2 females, aged 43-68 years with an average of 58 years. All cases were classified as stages III and IV before radiotherapy according to staging standard of oropharyngeal cancer (International Union Against Cancer, 1997). The time of relapse was 6-32 months after radiotherapy. Recurrent tonsil cancer invased tongue base, soft palate, posterior wall of pharyngeal, parapharyngeal space, and palate. Tumor size was from 4 cm × 2 cm to 8 cm × 5 cm. Seven cases were accompanied by lymph node metastasis. After carcinoma were completely resected and defects were reconstructed by pectoral is major myocutaneous flap of 7 cm × 5 cm- 12 cm × 9 cm. The donor sites were sutured directly. Results After operation, pectoral is major myocutaneous flap completely survived in 9 cases. Partial necrosis of pectoral is major myocutaneous flap was found in 1 case; after treatment, the necrotic flap remained small pharyngeal defect. Incision at donor site healed by first intention in 10 cases. All patients showed satisfactory functions of respiratory, voice, and swallowing with no compl ication. Ten patients were followed up 2 years to 5 years and 8 months. The 3-year survival rate was 66.7% (6/9), and the 5-year survival rate was 20.0% (1/5). Conclusion Pectoral is major muscle flap has a high survival rate, which is safe, rel iable, easy-to-operate, and can repair larger defect. Pectoral is major myocutaneous flap is an ideal material in repair of defect caused by resection of recurrent tonsillar carcinoma after radiotherapy.